Video based microscope adjustment

ABSTRACT

The present disclosure relates to an optical observation device which is controlled in a sterility preserving manner, and to a corresponding controlling program and/or program storage medium. The optical observation device includes a main structure having at least one optical camera, a support structure adapted to variably position the main structure, and a control unit that receives a sequence of images from the at least one optical camera, searches a current image from the sequence of images for a trackable object, tracks the trackable object shown in the sequence of images subsequent to the current image; and controls adjustable properties of AR-content superimposed with the sequence of images in accordance with a motion of the trackable object, wherein the adjustable properties of the AR-content include a location, orientation, and/or size of the AR-content with respect to the sequence of images.

RELATED APPLICATION DATA

This application is a continuation of U.S. patent application Ser. No.16/629,351, filed on Jan. 8, 2020, which is a national phase applicationof International Application No. PCT/EP2018/068818, filed on Jul. 11,2018, which claims priority to International Application No.PCT/EP2017/070487, filed on Aug. 11, 2017, all of which are incorporatedherein by reference in their entirety.

TECHNICAL FIELD

The present invention relates to an optical observation device which isadjusted in a sterility preserving manner by utilizing a hand-helddevice within the field of view of the observation device. The presentinvention further relates to a corresponding computer program run on anobservation device controller for adjusting such observation device.

BACKGROUND

During medical procedures optical observations devices such asmicroscopes or robotic arms with cameras attached to it may be utilizedin order to help surgical personnel to see small anatomical details of apatient to be treated. In this context it is often necessary to readjustthe optical observation device in order to look at one or even moredetails of interest from different positions. It may be even necessaryto move the whole observation device out of the working area forparticular steps of a medical workflow and to reposition the observationdevice thereafter, preferably at the same position. Moreover, it isdesirable to enable a plurality of persons to use the observationdevice, which requires a positional rearrangement, as well. Currently,optical observation devices such as microscopes are adjusted manually,for example by simply grasping handles of the device and by pressing abutton to release the break of an articulated support arm which isotherwise holding the device rigidly in place.

Other solutions make use of remote controls or foot pedals forcontrolling the device. Fully automatic controls for positioningmicroscopes are also known in the art, which however, prevent personnelto make adjustments by their own desire.

SUMMARY

The present invention provides an optical observation device which canbe easily controlled by medical personnel by their own desire andinitiative, and even in a sterility preserving manner.

The optical observation device of the present invention comprises:

a) a main structure comprising at least one optical camera;

b) a motorized support structure adapted to variably position the mainstructure at or near a workplace to be observed; and

c) a control unit adapted to perform the following procedural steps:

-   -   receive a sequence of images from the at least one optical        camera;    -   search a current image from the sequence of images for a        trackable object and track the trackable object shown in the        sequence of images subsequent to the current image;    -   receive a trigger signal for controlling the motorized support        structure, an optical set-up and/or the at least one optical        camera in accordance with a motion of the trackable object.

In other words, of the inventive observation device has, as a mainstructure, a microscope or a camera adapted to be aimed at an object ora patient to be treated and to provide a sequence of images thereof. Thesequence of images may form a video. In order to hold the microscope orcamera in place in or next to the object or the anatomical structure ofa patient to be observed, a support structure is provided which may beconnected at one end to the ceiling or a wall of a room, but may also beconnected to a mobile trolley. At its other end, the support structureholds the microscope or camera in a positionally fixed but yetadjustable position with respect to its first end and, since the patientis immobilized within the room as well, with respect to the object orthe anatomical structure of the patient. Thus, the relative positionbetween the main structure and the observed object or anatomy remainsunchanged until a user such as medical personnel decides otherwise.

For this case one specific embodiment of the inventive observationdevice comprises a control unit that causes the support structure tomove the main structure. For this purpose the control unit receives avideo from a camera of the main structure and searches this video for animage of a specific trackable and hand-held device that is utilized forcontrolling the observation device. As soon as the control unit receivesa signal indicating that personnel wishes the main structure to move inaccordance with the hand-held device, the control units sends controlsignals to the support structure, for example to one or more motors ofthe support structure such that the main structure is eventually movedin accordance with the motion of the hand-held device.

Additionally or alternatively to this motion-control and in accordancewith another specific embodiment of the present invention, the controlunit may send control signals to an optical set-up and/or to the atleast one optical camera of the main structure so as to adjust certainproperties such as the zoom factor or the focus of the optical set-up orthe optical camera in accordance with the motion of the hand-helddevice.

In summary, the inventive optical observation device can be adjusted invarious ways simply by moving a hand-held device within the field ofview of a microscope or an optical camera of the observation device.Since this does not require any physical interaction with theobservation device, the present invention not only allows for anintuitive and therefore simple possibility to control a medicalmicroscope or camera, but also helps in preserving sterility during anentire medical workflow.

In accordance with another embodiment of the present invention andalready indicated further above, the main structure may comprise or be asurgical microscope as used during a medical workflow for treating apatient. However, the present invention may also be utilized for anyother workflow apart from medical workflows, for which a touch-lesscontrol of an optical observation device is desired.

In accordance with a further embodiment of the present invention thecontrol unit is adapted to receive the trigger signal via a sterilitypreserving user interface, particularly via covering or uncovering anoptically recognizable feature provided on the trackable object, via afoot pedal switch, via voice command and/or via gestures which arerecognizable from the sequence of images. For example, a predefinedmotion of the hand-held device may be recognized in the video images.For example, turning the device around its longitudinal axis or rotatingone end of the device in a circular manner with the other end of thedevice being positionally fixed may be recognized as a triggeringgesture. As often used during medical procedures, optically recognizablemarkers (such as a marker spheres) or other designated optionallyrecognizable features may be provided on the instrument, which may alsobe recognized by a medical tracking system associated with a medicalnavigation system for calculating the spatial position of theinstrument, may be temporarily covered by the user so as to provoke atriggering signal.

According to another embodiment of the invention, the motion of the mainstructure, but also the adjustable properties of the optical set-upand/or optical camera, may be coupled to the motion of the trackableobject via at least one, particularly selectable conversion factor. Suchconversion factor may cause the motion of the main structure to beamplified or to be reduced and/or to be damped as compared to the motionof the trackable object. By doing so, moving the hand-held device by alarger distance will result in a respective adjustment of, for example,the position and/or the focus length by a smaller or even largerdistance as compared to the distance covered by the hand-held device.For obtaining a “smoother”, less “nervous” adjustment of the observationdevice, a damping factor may be interposed between the motion of thehand-held device and the controlled adjustment.

Further, it is conceivable that an upper threshold for the speed ofmotion of the hand-held device is defined such that motions above thethreshold are ignored. By doing so, abrupt or accidental and undesiredmotions will not result in also undesired adjustment of the observationdevice.

According to another embodiment of the present invention at least twodegrees of freedom for the motion of the main structure are controlledseparately, such that motion of the main structure in at least one ofthe at least two degrees of freedom is blocked while the main structureis controlled to move within at least one other of the at least twodegrees of freedom. Thus, an adjustment is performed only in certaindegrees of freedom which reduces the amount of undesired adjustment. Forexample a substantially vertical motion of the hand-held device willcause an adjustment in a vertical direction, while any other degrees offreedom for the adjustment are blocked. Thus, an “inaccurate” controlinput with a, in this case, slight horizontal deviation cannot lead toan unintended adjustment in a horizontal direction. In this context itis to be noted that adjustments can in principle be performed in all sixdegrees of freedom, three translational degrees of freedom and threerotational degrees of freedom. Of course, measures will have to beprovided that enable the user to “switch” between the plurality ofdegrees of freedom for respective adjustments.

In addition to the above described adjustments of the properties of theoptical observation device itself including, for example, the spatialposition, the zoom factor and the focus length, the present inventionmay also provide for further adjustments including the adjustment ofproperties of AR-content superimposed with the sequence of images,particularly the location, orientation and/or size of AR-content withrespect to the sequence of images; in accordance with a motion of thehand-held device.

Controlling the properties of AR content superimposed with the sequenceof images, particularly the location, orientation and/or size of ARcontent with respect to the sequence of images in accordance with amotion of the trackable object as described above may even be consideredas a separate invention without and independent of controlling themotorized support structure, the optical set-up and/or the at least oneoptical camera.

As already indicated further above, the trackable object may be ahand-held device or hand-held medical instrument, particularly a pointerinstrument as often utilized in medical procedures. Further, thehand-held device may be provided as a disposable device.

The hand-held device may be recognized on the video images via a ringpattern provided on the hand-held device, particularly the tip thereof.

A further aspect of the present invention relates to a program, whichwhen running on a processor of the control unit described above, causesthe processor to perform the above described procedural steps. An evenfurther aspect of the present invention relates to a program storagemedium on which such program is stored, in particular in anon-transitory form.

The system and the program system are defined by the appendedindependent claims. Advantages, advantageous features, advantageousembodiments and advantageous aspects of the present invention aredisclosed in the following and contained in the subject-matter of thedependent claims. Different advantageous features can be combined inaccordance with the invention wherever technically expedient andfeasible. Specifically, a feature of one embodiment which has the sameor a similar function to another feature of another embodiment can beexchanged with said other feature, and a feature of one embodiment whichadds an additional function to another embodiment can in particular beadded to said other embodiment.

Definitions

The procedure performed in accordance with the invention is for examplea computer implemented method. For example, all the steps or merely someof the steps (i.e. less than the total number of steps) of the method inaccordance with the invention can be executed by a computer (forexample, at least one computer). An embodiment of the computerimplemented method is a use of the computer for performing a dataprocessing method. An embodiment of the computer implemented method is amethod concerning the operation of the computer such that the computeris operated to perform one, more or all steps of the method.

The computer for example comprises at least one processor and forexample at least one memory in order to (technically) process the data,for example electronically and/or optically. The processor being forexample made of a substance or composition which is a semiconductor, forexample at least partly n- and/or p-doped semiconductor, for example atleast one of II-, III-, IV-, V-, VI-semiconductor material, for example(doped) silicon and/or gallium arsenide. The calculating steps describedare for example performed by a computer. Determining steps orcalculating steps are for example steps of determining data within theframework of the technical method, for example within the framework of aprogram. A computer is for example any kind of data processing device,for example electronic data processing device. A computer can be adevice which is generally thought of as such, for example desktop PCs,notebooks, netbooks, etc., but can also be any programmable apparatus,such as for example a mobile phone or an embedded processor. A computercan for example comprise a system (network) of “sub-computers”, whereineach sub-computer represents a computer in its own right. The term“computer” includes a cloud computer, for example a cloud server. Theterm “cloud computer” includes a cloud computer system which for examplecomprises a system of at least one cloud computer and for example aplurality of operatively interconnected cloud computers such as a serverfarm. Such a cloud computer is preferably connected to a wide areanetwork such as the world wide web (WWW) and located in a so-calledcloud of computers which are all connected to the world wide web. Suchan infrastructure is used for “cloud computing”, which describescomputation, software, data access and storage services which do notrequire the end user to know the physical location and/or configurationof the computer delivering a specific service. For example, the term“cloud” is used in this respect as a metaphor for the Internet (worldwide web). For example, the cloud provides computing infrastructure as aservice (IaaS). The cloud computer can function as a virtual host for anoperating system and/or data processing application which is used toexecute the method of the invention. The cloud computer is for examplean elastic compute cloud (EC2) as provided by Amazon Web Services™. Acomputer for example comprises interfaces in order to receive or outputdata and/or perform an analogue-to-digital conversion. The data are forexample data which represent physical properties and/or which aregenerated from technical signals. The technical signals are for examplegenerated by means of (technical) detection devices (such as for exampledevices for detecting marker devices) and/or (technical) analyticaldevices (such as for example devices for performing (medical) imagingmethods), wherein the technical signals are for example electrical oroptical signals. The technical signals for example represent the datareceived or outputted by the computer. The computer is preferablyoperatively coupled to a display device which allows informationoutputted by the computer to be displayed, for example to a user. Oneexample of a display device is an augmented reality device (alsoreferred to as augmented reality glasses) which can be used as “goggles”for navigating. A specific example of such augmented reality glasses isGoogle Glass (a trademark of Google, Inc.). An augmented reality devicecan be used both to input information into the computer by userinteraction and to display information outputted by the computer.Another example of a display device would be a standard computer monitorcomprising for example a liquid crystal display operatively coupled tothe computer for receiving display control data from the computer forgenerating signals used to display image information content on thedisplay device. A specific embodiment of such a computer monitor is adigital lightbox. The monitor may also be the monitor of a portable, forexample handheld, device such as a smart phone or personal digitalassistant or digital media player.

The invention also relates to a program which, when running on acomputer, causes the computer to perform one or more or all of themethod steps described herein and/or to a program storage medium onwhich the program is stored (in particular in a non-transitory form)and/or to a computer comprising said program storage medium and/or to a(physical, for example electrical, for example technically generated)signal wave, for example a digital signal wave, carrying informationwhich represents the program, for example the aforementioned program,which for example comprises code means which are adapted to perform anyor all of the method steps described herein.

The invention also relates to a navigation system for computer-assistedsurgery, comprising: the computer of the preceding claim, for processingthe absolute point data and the relative point data;

a detection device for detecting the position of the main and auxiliarypoints in order to generate the absolute point data and to supply theabsolute point data to the computer;

a data interface for receiving the relative point data and for supplyingthe relative point data to the computer; and

a user interface for receiving data from the computer in order toprovide information to the user, wherein the received data are generatedby the computer on the basis of the results of the processing performedby the computer.

Within the framework of the invention, computer program elements can beembodied by hardware and/or software (this includes firmware, residentsoftware, micro-code, etc.). Within the framework of the invention,computer program elements can take the form of a computer programproduct which can be embodied by a computer-usable, for examplecomputer-readable data storage medium comprising computer-usable, forexample computer-readable program instructions, “code” or a “computerprogram” embodied in said data storage medium for use on or inconnection with the instruction-executing system. Such a system can be acomputer; a computer can be a data processing device comprising meansfor executing the computer program elements and/or the program inaccordance with the invention, for example a data processing devicecomprising a digital processor (central processing unit or CPU) whichexecutes the computer program elements, and optionally a volatile memory(for example a random access memory or RAM) for storing data used forand/or produced by executing the computer program elements. Within theframework of the present invention, a computer-usable, for examplecomputer-readable data storage medium can be any data storage mediumwhich can include, store, communicate, propagate or transport theprogram for use on or in connection with the instruction-executingsystem, apparatus or device. The computer-usable, for examplecomputer-readable data storage medium can for example be, but is notlimited to, an electronic, magnetic, optical, electromagnetic, infraredor semiconductor system, apparatus or device or a medium of propagationsuch as for example the Internet. The computer-usable orcomputer-readable data storage medium could even for example be paper oranother suitable medium onto which the program is printed, since theprogram could be electronically captured, for example by opticallyscanning the paper or other suitable medium, and then compiled,interpreted or otherwise processed in a suitable manner. The datastorage medium is preferably a non-volatile data storage medium. Thecomputer program product and any software and/or hardware described hereform the various means for performing the functions of the invention inthe example embodiments. The computer and/or data processing device canfor example include a guidance information device which includes meansfor outputting guidance information. The guidance information can beoutputted, for example to a user, visually by a visual indicating means(for example, a monitor and/or a lamp) and/or acoustically by anacoustic indicating means (for example, a loudspeaker and/or a digitalspeech output device) and/or tactilely by a tactile indicating means(for example, a vibrating element or a vibration element incorporatedinto an instrument). For the purpose of this document, a computer is atechnical computer which for example comprises technical, for exampletangible components, for example mechanical and/or electroniccomponents. Any device mentioned as such in this document is a technicaland for example tangible device.

It is the function of a marker to be detected by a marker detectiondevice (for example, a camera or an ultrasound receiver or analyticaldevices such as CT or MRI devices) in such a way that its spatialposition (i.e. its spatial location and/or alignment) can beascertained. The detection device is for example part of a navigationsystem. The markers can be active markers. An active marker can forexample emit electromagnetic radiation and/or waves which can be in theinfrared, visible and/or ultraviolet spectral range. A marker can alsohowever be passive, i.e. can for example reflect electromagneticradiation in the infrared, visible and/or ultraviolet spectral range orcan block x-ray radiation. To this end, the marker can be provided witha surface which has corresponding reflective properties or can be madeof metal in order to block the x-ray radiation. It is also possible fora marker to reflect and/or emit electromagnetic radiation and/or wavesin the radio frequency range or at ultrasound wavelengths. A markerpreferably has a spherical and/or spheroid shape and can therefore bereferred to as a marker sphere; markers can however also exhibit acornered, for example cubic, shape.

A marker device can for example be a reference star or a pointer or asingle marker or a plurality of (individual) markers which are thenpreferably in a predetermined spatial relationship. A marker devicecomprises one, two, three or more markers, wherein two or more suchmarkers are in a predetermined spatial relationship. This predeterminedspatial relationship is for example known to a navigation system and isfor example stored in a computer of the navigation system.

In another embodiment, a marker device comprises an optical pattern, forexample on a two-dimensional surface. The optical pattern might comprisea plurality of geometric shapes like circles, rectangles and/ortriangles. The optical pattern can be identified in an image captured bya camera, and the position of the marker device relative to the cameracan be determined from the size of the pattern in the image, theorientation of the pattern in the image and the distortion of thepattern in the image. This allows determining the relative position inup to three rotational dimensions and up to three translationaldimensions from a single two-dimensional image.

The position of a marker device can be ascertained, for example by amedical navigation system. If the marker device is attached to anobject, such as a bone or a medical instrument, the position of theobject can be determined from the position of the marker device and therelative position between the marker device and the object. Determiningthis relative position is also referred to as registering the markerdevice and the object. The marker device or the object can be tracked,which means that the position of the marker device or the object isascertained twice or more over time.

A pointer is a rod which comprises one or more—advantageously,two—markers fastened to it and which can be used to measure offindividual co-ordinates, for example spatial co-ordinates (i.e.three-dimensional co-ordinates), on a part of the body, wherein a userguides the pointer (for example, a part of the pointer which has adefined and advantageously fixed position with respect to the at leastone marker attached to the pointer) to the position corresponding to theco-ordinates, such that the position of the pointer can be determined byusing a surgical navigation system to detect the marker on the pointer.The relative location between the markers of the pointer and the part ofthe pointer used to measure off co-ordinates (for example, the tip ofthe pointer) is for example known. The surgical navigation system thenenables the location (of the three-dimensional co-ordinates) to beassigned to a predetermined body structure, wherein the assignment canbe made automatically or by user intervention.

The present invention is also directed to a navigation system forcomputer-assisted surgery. This navigation system preferably comprisesthe aforementioned computer for processing the data provided inaccordance with the computer implemented method as described in any oneof the embodiments described herein. The navigation system preferablycomprises a detection device for detecting the position of detectionpoints which represent the main points and auxiliary points, in order togenerate detection signals and to supply the generated detection signalsto the computer, such that the computer can determine the absolute mainpoint data and absolute auxiliary point data on the basis of thedetection signals received. A detection point is for example a point onthe surface of the anatomical structure which is detected, for exampleby a pointer. In this way, the absolute point data can be provided tothe computer. The navigation system also preferably comprises a userinterface for receiving the calculation results from the computer (forexample, the position of the main plane, the position of the auxiliaryplane and/or the position of the standard plane). The user interfaceprovides the received data to the user as information. Examples of auser interface include a display device such as a monitor, or aloudspeaker. The user interface can use any kind of indication signal(for example a visual signal, an audio signal and/or a vibrationsignal). One example of a display device is an augmented reality device(also referred to as augmented reality glasses) which can be used asso-called “goggles” for navigating. A specific example of such augmentedreality glasses is Google Glass (a trademark of Google, Inc.). Anaugmented reality device can be used both to input information into thecomputer of the navigation system by user interaction and to displayinformation outputted by the computer.

A navigation system, such as a surgical navigation system, is understoodto mean a system which can comprise: at least one marker device; atransmitter which emits electromagnetic waves and/or radiation and/orultrasound waves; a receiver which receives electromagnetic waves and/orradiation and/or ultrasound waves; and an electronic data processingdevice which is connected to the receiver and/or the transmitter,wherein the data processing device (for example, a computer) for examplecomprises a processor (CPU) and a working memory and advantageously anindicating device for issuing an indication signal (for example, avisual indicating device such as a monitor and/or an audio indicatingdevice such as a loudspeaker and/or a tactile indicating device such asa vibrator) and a permanent data memory, wherein the data processingdevice processes navigation data forwarded to it by the receiver and canadvantageously output guidance information to a user via the indicatingdevice. The navigation data can be stored in the permanent data memoryand for example compared with data stored in said memory beforehand.

BRIEF DESCRIPTION OF DRAWINGS

In the following, the invention is described with reference to theenclosed FIGURE which represents a preferred embodiment of theinvention. The scope of the invention is however not limited to thespecific features disclosed in the FIGURE, which shows:

FIG. 1 an optical observation device in accordance with the presentinvention controlled via a hand-held pointer instrument.

DETAILED DESCRIPTION

The optical observation device 1 shown in FIG. 1 comprises, as a mainstructure, a surgical microscope 2 which is held above a workplace by anarticulated support structure 5 which is, at its other end, connected toa mobile wheel trolley.

The spatial position of the microscope 2 with respect to the trolley andtherefore also with respect to the workplace is adjusted by activatingmotorized joints 9 between the arm sections 8 of the articulated supportarm 5.

In accordance with the present invention, this is done with the help ofa pointer instrument 7 which is positioned within the field of view ofthe microscope. By covering an optically detectable feature 12 on theinstrument 7 (which has to be at this time within the microscope's fieldof view and may be a colored spot or marking; even tracking markers orone or more rings of the ring pattern 13 may act as the feature 12) orby pushing the foot pedal switch 11 which is connected to an interface10 of the control unit 6, a triggering signal is provoked that sets offthe following control procedure:

The spatial position of a ring pattern 13 which is provided at the tipof the instrument 7 is determined within the sequence of images thecontrol unit 6 receives from the cameras 4 of the microscope 2. As soonas the instrument 7 is moved by a user within the field of view of themicroscope, the control unit 6 controls the motorized joints 9 such thatthe microscope 2 “follows” the ring pattern 13 on the instrument 7.Since “exaggerated” microscope motions are undesired, the microscope 2will move by a smaller distance than the instrument 7 does. Obviously,the ring-pattern 13 is not suitable for controlling the microscope 2 inaccordance with a rotation of the instrument 7 around its longitudinalaxis. However, other features recognizable for the cameras 4 or even foran external medical tracking system may be provided to allow fortracking this motion as well. Provided that all six degrees of freedom(x′, y′, z′, u′, v′, w′) are recognized within the field of view of themicroscope 2, the position of the microscope 2 can in principle beadjusted in six degrees of freedom (x, y, z, u, v, w). Even though theabove lines describe a positional adjustment of the microscope 2 withrespect to a medical workplace underneath the microscope 2, theproperties of an optical set-up 3 of the microscope 2 or the cameras 4of the microscope 2 may alternatively or additionally be adjusted via amotion of the instrument 7 in the same manner as described above. Forexample, the focal length of the optical set-up 3 of the microscope 2may be adjusted by moving the instrument 7 in a vertical direction. In afurther example, the zoom factor of the microscope cameras 4 may beadjusted by moving the instrument 7 in a horizontal or even in avertical direction.

1.-13. (canceled)
 14. An optical observation device comprising: a main structure comprising a surgical microscope having at least one optical camera adapted to be aimed at a patient to be treated; a support structure adapted to variably position the main structure at or near a workplace to be observed; and a control unit adapted to: receive a sequence of images from the at least one optical camera; search a current image from the sequence of images for a trackable object positioned within a field of view of the at least one optical camera; track the trackable object shown in the sequence of images subsequent to the current image; and control properties of AR-content superimposed with the sequence of images in accordance with a motion of the trackable object, the properties of the AR-content including a location, orientation, and/or size of the AR-content with respect to the sequence of images.
 15. The optical observation device according to claim 14, wherein the control unit is further adapted to control properties of an optical set-up including a focus-point of the optical set-up and/or to control properties of the at least one optical camera including a zoom-factor of the at least one optical camera in accordance with the motion of the trackable object.
 16. The optical observation device according to claim 14, wherein an upper threshold for a speed of motion of the trackable object is defined and motions above the upper threshold are ignored.
 17. The optical observation device of claim 14, wherein a handheld medical instrument is recognized as the trackable object, which is provided as a disposable device.
 18. The optical observation device according to claim 17, wherein the medical instrument is tracked via a ring pattern provided on the medical instrument and visible in the sequence of images.
 19. The optical observation device of claim 14, wherein the support structure is a motorized support structure and the control unit is further adapted to control the motorized support structure, an optical set-up and/or the at least one optical camera, wherein motion of the main structure, and/or adjustable properties of the optical set-up and/or of the at least one optical camera, is coupled to the motion of the trackable object via at least one conversion factor.
 20. The optical observation device according to claim 19, wherein at least two degrees of freedom for the motion of the main structure are controlled separately, such that motion of the main structure in at least one of the at least two degrees of freedom is blocked while the main structure is controlled to move within at least one other of the at least two degrees of freedom.
 21. The optical observation device according to claim 19, wherein the control unit is adapted to receive a trigger signal for controlling the motorized support structure, the optical set-up and/or the at least one optical camera, in accordance with the motion of the trackable object, via a sterility preserving user interface, via covering or uncovering an optically recognizable feature provided on the trackable object, wherein the trigger signal is activated by a foot pedal switch, voice command, and/or gestures which are recognizable from the sequence of images.
 22. The optical observation device according to claim 19, wherein the motorized support structure is controlled to move the main structure in accordance with the motion of the trackable object, wherein the motorized support structure is an articulated arm with at least two arm sections which are hingedly connected to each other via at least one motorized joint.
 23. The optical observation device according to claim 22, wherein the motion of the main structure is coupled to the motion of the trackable object via the at least one conversion factor causing: the motion of the main structure to be amplified as compared to the motion of the trackable object; the motion of the main structure to be reduced as compared to the motion of the trackable object; and/or the motion of the main structure to be damped as compared to the motion of the trackable object.
 24. An optical observation device comprising: a main structure comprising at least one optical camera adapted to transmit a sequence of images; a support structure adapted to move the main structure; and a control unit adapted to receive the sequence of images from the optical camera, track a trackable object shown in the sequence of images, and control properties of AR-content superimposed with the sequence of images in accordance with a motion of the trackable object, wherein the properties of the AR-content include a location, orientation, and/or size of the AR-content with respect to the sequence of images.
 25. The optical observation device according to claim 24, wherein the control unit is further adapted to search a current image from the sequence of images for the trackable object after receipt of the sequence of images.
 26. The optical observation device according to claim 25, wherein the support structure is a motorized support structure and the control unit is further adapted to transmit a signal to the motorized support structure of where to move the main structure in accordance with the motion of the trackable object via at least one conversion factor, wherein the control unit is further adapted to receive a trigger signal for controlling the motorized support structure in accordance with the motion of the trackable object.
 27. The optical observation device according to claim 26, wherein the motion of the main structure is coupled to the motion of the trackable object via the at least one conversion factor causing the motion of the main structure to be reduced as compared to the motion of the trackable object, and/or the motion of the main structure to be damped as compared to the motion of the trackable object.
 28. The optical observation device according to claim 24, wherein the control unit is further adapted to control properties of an optical set-up including a focus-point of the optical set-up and/or to control properties of the at least one optical camera including a zoom-factor of the at least one optical camera in accordance with the motion of the trackable object.
 29. The optical observation device according to claim 24, wherein the support structure is a motorized support structure and the control unit is further adapted to transmit a signal to the motorized support structure of where to move the main structure in accordance with the motion of the trackable object via at least one conversion factor.
 30. The optical observation device according to claim 29, wherein the motorized support structure is controlled to move the main structure in accordance with the motion of the trackable object, and wherein the motorized support structure is an articulated arm with at least two arm sections which are hingedly connected to each other via at least one motorized joint.
 31. The optical observation device according to claim 29, wherein the control unit is adapted to receive a trigger signal for controlling the motorized support structure, via a sterility preserving user interface, via covering or uncovering an optically recognizable feature provided on the trackable object, wherein the trigger signal is activated by a foot pedal switch, voice command, and/or gestures which are recognizable from the sequence of images.
 32. The optical observation device according to claim 31, wherein covering a designated feature of the trackable object, which is visible to the at least one optical camera is recognized as a gesture provoking the trigger signal.
 33. A program logic stored in a memory device of a computer, that when the program logic is executed by the computer causes the computer to: receive a sequence of images from at least one optical camera; search a current image from a sequence of images for a trackable object; track the trackable object shown in the sequence of images subsequent to the current image; and control adjustable properties of AR-content superimposed with the sequence of images, adjustable properties of an optical set-up, and/or adjustable properties of the at least one optical camera in accordance with motion of the trackable object, wherein the adjustable properties of the AR-content include a location, orientation, and/or size of the AR-content with respect to the sequence of images. 